URGENT action is needed to tackle the worrying increase in the number of children being struck down with the hospital "superbug" MRSA, researchers said yesterday.

Hospital-acquired infections strike around 100,000 people each year in England, costing £1bn and resulting in an estimated 5,000 deaths.

The vast majority of cases of superbug methicillin resistant staphylococcus aureus - which is resistant to antibiotics - occur in adults because they tend to spend more time in hospital where it is most commonly picked up.

But researchers from St George's Hospital in south London and the Health Protection Agency (HPA) said the increasing numbers of children being struck down with MRSA was a cause of concern for parents and doctors.

Between 1990 and 2001, there were 376 cases of MRSA among under-15s in England and Wales, with more than half of those cases (53%) in those under a year old.

Numbers have increased steadily from just four cases in 1990 to 77 in 2000.

The researchers said: "The increasing proportion of MRSA bacteraemia in children is a cause for concern for both patients and clinicians.

"MRSA bacteraemia is associated with a higher mortality rate, longer hospital stay, and is a significant independent risk factor for death."

The team said that, although MRSA was still not as common in children as adults, steps were needed to stop it escalating further.

"We recommend an urgent national review identifying the risk factors for MRSA acquisition on neonatal and paediatric units, and the infection control measures in place," they said.

Dr Jim Gray, of the Department of Microbiology at Birmingham's Children's Hospital, said the spread of MRSA in children was of "considerable concern".

But it should be possible to take action now to stop it getting worse.

"Recent data on MRSA in children suggest that paediatrics may be where adult practice was in the mid 1990s.

"If that is so, then there should still be an opportunity to halt, and even reverse, the current increase in MRSA in children," he said.

In December, Chief Medical Officer Sir Liam Donaldson announced that "bug-buster" bosses would be appointed in every hospital to impose strict rules to cut infections.